You do not need to be connected to the internet while using VCDS to scan a car, but it is required for initial software updates or firmware registration.
VCDS Update 20.12.0 https://www.ross-tech.com ... - Facebook
To run VCDS 20.12 effectively, your system should meet these minimum specs: : Windows 7, 8, 10, or 11 (32-bit or 64-bit).
Grab your laptop, head to the garage, and see what your car is really trying to tell you.